What are the thoughts on resistors made by Burster?
We haven't talked about them yet. They say that they can achieve <2ppm/K with selecting materials and Zeranin, but also do some "meticulous artificial aging procedure".
I've been told that in a quantity of 10 a single resistor (1142) is about 23,13€.
Hello branadic,
I also thougth of them. Another option could be Powertron.
My personal opinion is: If you can get a matched set of resistors for a voltage divider
with even narrower specs or a special resistor value this could be fine.
For a single resistor with low TC I see no advantage against a Z201 with similar price for a single unit.
On the other side I stumbled over the Riedon T.C. curves:
http://www.riedon.com/media/pdf-tech/TemperatureandTC.pdfwhat the hell does the statement "The TC adjustment is per charge at the reference temperature of 25°C (T0)." really mean?
I fear my english is too bad to fully understand what they want to express here.
And what does this mean together with the "picture 2" with the mean value on -1.8ppm/deg?
Ok I know that T.C. curves of resistor manufacturers are never true since they test only at exact 3 temperatures.
25 deg, -55 deg and +125 deg. All other values inbetween are interpolated.
But for me the interesting part is the behaviour around 25 degrees.
I do not want to do precision measurements around -55 deg on north pole or in the sauna at 125 deg C.
By the way I´m still working on the theme but have no spectacular results at the moment.
In the mean time I found a systematical error in my calculations.
But since the (non-linear) error of 0.008 ppm cannot be seen in the curves it´s not worth to mention.
On the other side today I tested a buffer amplifier between multiplexer and ADC.
There is also no significant change against unbuffered mode.
But the buffer will allow me to use much larger resistor values (than the 1K) together with the ADC
without running into trouble with non-linearities.
With best regards
Andreas